Method for retrieiving medication packages

ABSTRACT

The present disclosure relates to a method for retrieving medication packages from a pharmacy order-picking device. In modern pharmacy order-picking devices, medication packages are stored for space optimization, which can cause a number of heavy packages to be stored on one shelf, causing the shelf to bend, which may prevent retrieval. In the method according to the disclosure, an operating device ( 20 ) is displaced in a displacement position to a predetermined shelf position, at least one medication package ( 30 ) on a shelf ( 11 ) belonging to the shelf position is moved with a gripping device ( 22 ) in the direction of a support ( 21 ) and it is then checked whether the at least one medication package ( 30 ) has moved fully onto the support ( 21 ). If the check has a negative outcome, an edge ( 11″, 11 ′″) of the shelf ( 11 ) on which the at least one medication package is stored is detected with a sensor ( 23 ) of the operating device ( 20 ) and said operating device ( 20 ) is displaced to a corresponding shelf position, the gripping device ( 22 ) having been brought into the displacement position before displacement.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/375,778, entitled “METHOD FOR RETRIEVING MEDICATION PACKAGES,” filedJul. 30, 2014, which is the U.S. National Phase application under 35U.S.C. §371 of International PCT Application No. PCT/EP2013/051302,filed on Jan. 24, 2013, which claims the benefit of European PatentApplication No. 12153133.9, filed Jan. 30, 2012. The entire contents ofthese applications are incorporated by reference herein.

BACKGROUND

In some pharmacy order-picking devices, a large number of various anddifferently-dimensioned medication packages (piece goods) are storedchaotically and in a space-optimized manner on elongated shelf bases.These shelf bases form, together with the shelf walls, a plurality ofshelf compartments, wherein a large number of medication packages isstored per shelf compartment, i.e., per shelf base.

The shelf bases typically consist of glass and are suspended in theshelf walls. The total weight of the medication packages stored pershelf space can vary strongly because of the multiplicity of themedication packages placed per shelf base and the space-optimized mannerof the storage. The shelf bases are designed such that they only sagminimally if they are occupied with medication packages of averageweight, whereby a retrieval with the aid of the operating device is notdisturbed.

To retrieve the medication packages, the operating device is moved to aspecific shelf position which is known to a control device of thepharmacy order-picking device. In the case of normal occupation of theshelf base, in this shelf position, the support surface of the supportof the operating device is approximately aligned horizontally with thesurface of the shelf base, so that the medication package to beretrieved or the medication packages to be retrieved can be moved usingthe gripping device without problems from the shelf base onto thesupport. The gripping device or the gripper includes clamping jaws,using which the medication package(s) is/are clamped and then moved ontothe support. The gripping device can furthermore include a vacuumsuction unit, using which medication packages can be moved onto thesupport. The vacuum suction unit can be used together with the clampingjaws or without them in dependence on the type of the medicationpackage.

SUMMARY

If a shelf base is occupied with an excessively high number ofrelatively heavy medication packages, the shelf base sags so stronglybecause of the material that the surface of the shelf base, when theoperating device is moved to the shelf position (target position)provided for the shelf base, no longer horizontally aligns with thesupport surface of the support. If a medication package is moved fromthe shelf base onto the support in such a case, the end side or end faceof the support can form a stop in the extreme case, which prevents afurther movement of the medication package onto the support, so that thedesired medication package cannot be retrieved from the pharmacyorder-picking device.

The present disclosure relates to a method for retrieving medicationpackages. In particular, the present disclosure relates to a method forretrieving medication packages from a pharmacy order-picking devicehaving at least one row of shelves having in each case a plurality ofshelf bases extending in a horizontal direction and a plurality of shelfwalls extending in a vertical direction, at least one operating devicewhich is movable horizontally and vertically in front of the row ofshelves, wherein the operating device includes a gripping device or agripper for storing and/or retrieving medication packages on or from theshelf base, a sensor, and a support having a support surface.

The object of the present disclosure is therefore to provide a methodfor retrieving medication packages from a pharmacy order-picking device,in which the retrieval is also possible from shelf bases equipped withparticularly heavy medication packages.

The pharmacy order-picking device, in which a method described herein isapplicable, includes at least one row of shelves having in each case aplurality of shelf bases extending in a horizontal direction (Xdirection, X axis) and a plurality of shelf walls extending in avertical direction (Z direction, Z axis), wherein the shelf bases andthe shelf walls form a plurality of shelf compartments. The pharmacyorder-picking device furthermore includes at least one operating device,which is movable horizontally and vertically in front of the row ofshelves, wherein the operating device itself includes a gripping deviceor a gripper for storing and/or retrieving medication packages on orfrom the shelf base, a sensor, and a support having a support surface.

The gripping device can include a jaw gripper havinglongitudinally-adjustable clamping jaws and/or a suction gripper (theactual gripping units). The support can be implemented, for example, asa simple support table, as guide rails, or as a conveyor belt. Thesensor can be arranged below the support or above the support, whereinthe arrangement of the sensor favors specific embodiments of a methoddescribed herein.

In a method described herein, the operating device is firstly moved viaan arrangement made of a horizontal guide and a vertical guide to apredefined shelf position, wherein the gripping device is located inthis case in a movement setting, in which the actual gripping units(clamping jaws, suction grippers) are positioned such that a free unitof the operating device within the pharmacy order-picking device ispossible. Under “normal conditions,” the shelf position is selected sothat the surface of the shelf base, from which the medication packagingis to be retrieved, is aligned horizontally with or is arranged slightlyhigher than (for example, 1 mm) the support surface of the support ofthe operating device. In the scope of this application, the term“medication package” is to be interpreted as “at least one medicationpackage”; this is also to comprise the retrieval of a plurality of(successively) stored medication packages.

As soon as the shelf position is approached, the medication package onthe shelf base associated with the shelf position is moved in thedirection toward the support using the gripping device. How this occursprecisely is not essential in the case of a method described herein. Ifa jaw gripper is used, the medication package is clamped using theclamping jaws and drawn onto the support. The movement onto the supportcan be assisted by the suction gripper or also can be carried out solelyby the suction gripper.

It is checked whether the medication package is moved completely ontothe support. This check can accompany the movement of the medicationpackage onto the support, i.e., it can be carried out simultaneouslywith the movement. This can be checked, for example, using an additionalsensor of the gripping device.

Alternatively, after ending a movement sequence, which is necessaryunder “normal” circumstances (i.e., without a disturbance of themovement from the shelf base onto the support) for the movement of themedication package onto the support, it can be checked whether the atleast one medication package has been moved completely onto the support.If so, the medication package can be transported using the operatingdevice to the delivery point of the pharmacy order-picking device.

However, if the check has a negative result, i.e., the medicationpackage has not been moved completely onto the support, an edge (topedge or bottom edge) of the shelf base, on which the medication packageis stored, is ascertained using the sensor of the operating device andthe operating device is moved to a correspondingly corrected shelfposition (at which retrieval can be performed without problems), whereinthe gripping device was moved into the movement setting before themovement. This can occur, for example, during the (attempted) movementof the medication package onto the support. If the gripping units of thegripping device have not been completely retracted during the movementof the medication package in the direction onto the support, thegripping units are completely retracted (movement setting) before themovement of the operating device to the corrected shelf position, sothat a free movement of the operating device is possible.

In this corrected shelf position, the surface of the shelf base and thesupport surface of the support are aligned in relation to one anothersuch that a problem-free movement from the shelf base onto the supportis possible, without the end face of the support forming a stop for themedication package. The shelf position is typically selected such thatthe surface of the shelf base is aligned horizontally with the supportsurface of the support or the support surface of the support is arrangedslightly below the surface of the shelf base.

The concept of the sensor is to be understood in the scope of thisapplication as a distance sensor having a unit for emitting measurementbeams and for receiving measurement beams, wherein the two units can becombined into one unit. During the distance determination, the sensorcan detect the direction or runtime of an actively emitted signal whichis reflected on a surface (of a medication package or a component of thepharmacy order-picking device). The distance determination can also becarried out capacitively or on the basis of the parallax or a stereoimage of an electronic camera, however.

In pharmacy order-picking devices, laser distance sensors, which operateaccording to the principle of laser triangulation, are typical. In thiscase, a laser beam is oriented onto a surface (see above) and observedusing the receiving unit (for example, camera, photodiode, diode array)located in the sensor. If the distance of the surface from the sensorchanges, the angle at which the light spot is observed, and thereforethe position of the image on the receiver of the receiving unit, alsochanges. For example, if a diode array is used, the diode which detectsthe reflected light beam changes with the distance. The distance of thesurface from the sensor can be calculated from the position change.

For reasons of cost, the distance measurement is generally carried outas a “single-point measurement.” That is, the measurement beam isemitted at a constant angle and is incident, without movement of theoperating device, on the same point (single point). The reflected beamis typically detected using a diode array.

The distance measurement can be carried out in this case so that onlythe detection at a specific diode (or a diode bundle) of the array isdifferentiated from the detection outside this diode or the diodebundle. The distance measurement then only recognizes two states(“binary distance measurement” hereafter).

In a method described herein, it is ensured that a retrieval can becarried out in spite of a sagging shelf base. If it is established thatthe movement of the medication package onto the support cannot becarried out, the actual position or the actual value (in relation to theZ axis) of an edge (top edge or bottom edge) of the shelf base isascertained using the sensor. In the event of sagging of the shelf base,this actual position deviates from the target position; the operatingdevice (and therefore the support) is effectively “positioned”excessively high for a retrieval of the medication package. Theoperating device is then moved vertically by a value corresponding tothe deviation, so that the retrieval is possible without problems.

As already indicated, the sensor of the operating device can be arrangedabove or below the support. Because of this arrangement within theoperating device, various alternative embodiments are conceivable orpreferable.

If the sensor is positioned above the support, the ascertainment of thetop edge of the shelf base, on which the medication package is stored,and the movement of the operating device to a corresponding shelfposition can be carried out such that the operating device is firstlymoved horizontally, until the sensor detects a region adjacent to themedication package to be retrieved.

If a laser distance sensor is used, for example, the sensor continuouslydetects the distance to the non-retrieved medication package. If thispackage ends, the distance increases suddenly; the sensor then eitherdetects the distance to the shelf back wall (this is known) or to amedication package located farther back. The shelf base is not occupiedin the region adjacent to the medication package as a result of therequired spacing of the medication packages from one another (inrelation to the X axis of the shelf compartments or the shelf bases). Ifonly a “binary” distance measurement is carried out, when themeasurement beam is guided over the end of the non-retrieved medicationpackage, the “state” (0/1) changes because of the sudden change of thedistance and the change thus caused of the detecting diode or thedetecting diode bundle.

The operating device is then moved downward at this position until asignal characterizing the top edge of the shelf base is ascertainedusing the sensor (if a laser distance sensor is used, the sudden changeof the distance between shelf back wall/rear medication package and topedge or end side of shelf base again; in the case of “binary” distancemeasurement, state change again). As soon as the characterizing signalis ascertained, the operating device is moved to a corresponding shelfposition, at which the medication package can be retrieved.

In another method, a bottom edge of the shelf base is ascertained andthe operating device is moved to a corresponding shelf position, bymoving the operating device vertically until a signal characterizing thebottom edge of the shelf base is ascertained using the sensor. Theoperating device is then moved to a correspondingly corrected shelfposition, at which the medication package is retrieved. How theoperating device is to be moved along the Z axis results from the knownthickness of the shelf base and the construction of the operating device(arrangement of sensor to support surface). Depending on whether thesensor is arranged above or below the support in the operating device,the operating device is moved upward (sensor below the support) ordownward (sensor above the support) along the Z axis.

In a further alternative embodiment of a method described herein, inwhich the sensor can again be arranged below or above the support, anedge (top edge/bottom edge) of the shelf base is ascertained and theoperating device is moved to a corresponding shelf position, by firstlyascertaining an actual position of the edge of the shelf base using thesensor, comparing the actual position to a target position, andvertically moving the operating device by a value corresponding to theascertained deviation.

In the case of this movement control, it is thus firstly ascertainedusing the sensor by which value the shelf base is offset downward, andthe operating device is subsequently moved by a corresponding value, sothat a retrieval from the sagging shelf base is possible withoutproblems.

In contrast to an above-mentioned variant of the method, in thisembodiment, the operating device does not first have to be moved in thehorizontal direction to ascertain the actual position of the top edge ofthe shelf base. This has the advantage that this method variant can becarried out more rapidly. However, the demands placed on the sensorsystem are greater. Either a two-dimensional or three-dimensionaldistance measurement is carried out or the sensor for the single pointmeasurement is pivotable or rotatable about the horizontal axis, whereinthe sudden distance change or “flank” (medication package/shelf backwall; shelf back wall/glass base) is not usable as a characteristicsignal, if the sensor is not also pivotable or rotatable about thevertical axis. In this method, other characteristic signals canoptionally be analyzed; for example, the front edge of the shelf basecan have a special coating, which is recognized by a correspondingsensor. However, details with respect to the sensor system are notessential for the present application; rather, a signal characterizingthe actual position of the top edge of the shelf base (and therefore ofthe shelf base itself, of course) is ascertained using the sensor.

After the ascertainment of the edge of the shelf base, the operatingdevice is moved to a correspondingly corrected shelf position. The shelfposition is selected such that a movement of the medication package fromthe glass base onto the support is possible. For this purpose, thesupport surface of the support of the operating device is to be alignedto the surface of the shelf base, on which the medication package isstored. To carry out the retrieval as rapidly as possible and withoutdamage, it is preferable for the operating device to be moved such thatthe support surface of the support is aligned horizontally with or isarranged lower by an amount Z than the shelf base surface of the shelfbase on which the medication package is stored. A typical value for Z is1 mm in this case, wherein a greater value for Z can also be used, ifthe composition of the support allows this.

In the course of the method, it is checked whether the medicationpackage is moved completely onto the support. Such a check is carriedout in a preferred embodiment such that the length of the medicationpackage moved onto the support is ascertained using a sensor and iscompared to a target value, which is stored in a control unit of thepharmacy order-picking device, wherein a deviation from a target valueindicates that the medication package was not moved completely onto thesupport. The length of the medication package can be ascertained in thiscase, for example, so that at known movement velocity of the medicationpackage onto the support, the interruption duration of a light barrier,for example, is ascertained. Alternatively, a contact sensor can bearranged on the support, which measures the contact duration at knownmovement velocity of the medication package, or ascertains whether thecontext sensor is released again after ended movement of the medicationpackage onto the support. In the latter case, this would mean that themovement sensor is arranged in the vicinity of the front edge of thesupport. The two above-mentioned embodiments allow a reliable andcost-effective check.

The gripping units of the gripping devices comprise a drive, which isresponsible for the movement of the gripping units into or out of theshelf compartment. The drive includes positioning regulators, whichcontinuously report their actual position. In the case of predefinedactual position of the drive or the positioning regulators, it canalternatively be checked using the sensor whether the medication packagewas moved onto the support.

In one embodiment of the method, the operating device, after it has beenmoved horizontally into the region adjacent to a medication package, ismoved downward until a signal characterizing the top edge of the shelfbase is ascertained using the sensor. The operating device issubsequently then moved to a shelf position in front of the medicationpackage and the medication package is retrieved. This embodiment of themethod can be expanded such that after the ascertainment of a signalcharacteristic for the top edge of the shelf base, the operating deviceis moved farther downward, ascertains a signal characteristic for thebottom edge, a plausibility check is carried out on the basis of theascertained signals, and, if the plausibility check is positive, theoperating device is then moved to the shelf position at which themedication package can be retrieved.

During the plausibility check, it is checked whether the thickness ofthe shelf base ascertained on the basis of the characteristic signalsfor the top edge and the bottom edge of the shelf base corresponds to atarget value. If this is not the case, in the event of previoushorizontal movement of the operating device, it is not moved to a pointat which a medication package is no longer arranged on the top edge ofthe shelf base. The above-mentioned embodiment of the method increasesthe reliability during the retrieval of medication packages.

In a further preferred embodiment, the operating device, after it hasbeen established that the medication package was not moved completelyonto the support, can be moved upward again until the top edge of themedication package to be retrieved is ascertained using the sensor. Thesag of the shelf base may be ascertained on the basis of the knownpackage height. As soon as the top edge of the medication package hasbeen ascertained, the operating device is moved downward again for theretrieval of the medication package.

In a preferred embodiment of the method, in which the sensor is arrangedbelow the support, if the check as to whether the medication package hasbeen moved completely onto the support has a negative result, themedication package is moved away from the support using the grippingdevice such that the at least one medication package has no contact withthe end face of the support. If the gripping device includes a vacuumsuction unit, the medication package can be pushed away from the topedge into the shelf compartment. Alternatively, the medication packagecan be pushed using the clamping jaws of the gripping device into theshelf compartment. In a further embodiment, the operating device cancomprise a pusher, using which the medication package can be pushedback. If the medication package has been pushed back, the operatingdevice can be moved upward without the location of the medicationpackage being changed by the support.

In a further preferred embodiment of the method, the medication packageis moved using the gripping device away from the support such that thetop edge of the shelf base is released before the gripping device ismoved into the movement setting. If the medication package has beenpushed, the operating device is moved downward until a signalcharacterizing the top edge of the shelf base is ascertained using thesensor. Finally, the operating device (if necessary at all) is moved toa shelf position at which the medication package is retrieved.

Alternatively, the pharmacy order-picking device includes at least onerow of shelves having in each case a plurality of shelf bases extendingin a horizontal direction and a plurality of shelf walls extending in avertical direction, and at least one operating device which is movablehorizontally and vertically in front of the row of shelves, wherein theoperating device includes a gripping device for storing and/orretrieving medication packages on or from the shelf base, a sensor, anda support having a support surface, wherein the sensor is arranged belowthe support in the operating device.

In the alternative method, the operating device is moved in a movementsetting to a predefined shelf position, at which the at least onemedication package is to be retrieved. If the shelf base correspondingto the shelf position is “normally” occupied, and no sagging as a resultof an occupation with numerous heavy medication packages is present, theat least one medication package can be retrieved at this shelf position.

As soon as the shelf position is reached, the distance A_(I) from thesensor to the bottom side of the shelf base is ascertained using thesensor, the distance A_(I) is compared to a target value A_(S) for thedistance between the sensor and the bottom side of the shelf base, andif a deviation which exceeds a limiting value is present between theascertained distance A_(I) and the target value A_(S), the operatingdevice is moved vertically by a corresponding amount to a correctedshelf position and the at least one medication package on the shelf baseassociated with the shelf position is moved in the direction of thesupport using the gripping device.

In contrast to the above-mentioned method, in the alternative solution,it is first checked whether the alignment of the operating device to theshelf base from which retrieval is to be performed is correct. For thispurpose, the distance sensor/bottom side of shelf base is measured andcompared to a target value. If no deviation exists, the support surfaceand the surface of the shelf base are horizontally aligned such that amovement of the medication package can be carried out without problems.If a deviation exists, it is ascertained on the basis of this deviation(and the knowledge about the precise construction of the row of shelvesand the operating device) how far the operating device may be movedvertically (generally downward) to reach a suitably corrected shelfposition for the retrieval.

Methods will be described in greater detail hereafter on the basis ofpreferred embodiments illustrated in the drawing, wherein only a sectionof a pharmacy order-picking device having operating device isschematically illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1a-1f show an embodiment of a method according to the disclosure.

FIGS. 2a-2f show a further embodiment of a method according to thedisclosure.

FIGS. 3a-3c show a further embodiment of a method according to thedisclosure.

FIG. 4 shows a further embodiment of a method according to thedisclosure.

FIGS. 5a and 5b show an embodiment of an alternative method according tothe disclosure.

DETAILED DESCRIPTION

FIGS. 1a-1f illustrate an embodiment of a method, wherein the structuralfeatures of the pharmacy order-picking device are only schematicallyshown. The embodiment shown here is suitable for operating devices inwhich the sensor 23 is installed above the support 21.

In some methods, the operating device 20 is first moved in a movementsetting, in which gripping units 22′ (clamping jaws here) of thegripping device 22 are arranged such that a free movement of theoperating device 20 in the pharmacy order-picking device is possible, toa predefined shelf position. The predefined shelf position isillustrated in FIGS. 1a-1d . The predefined shelf position represents aposition, in which medication packages can be retrieved without problemsin the case of a “normal” occupation of a shelf base; this shelfposition is stored in a control unit (not shown) of the pharmacyorder-picking device.

The shelf base 11 shown in FIGS. 1a-1f , as a result of loading with ahigh number of heavy medication packages, sags downward, so that thesurface 11′ of the shelf base 11 does not align horizontally with thesupport surface 21′ of the support 21 of the operating device 20. Sincethe medication packages are only deposited in a space-optimized manneron the shelf base, however, no items of information about (possible)sagging of the shelf base 11 are provided to the control unit. After thepositioning of the operating device 20 (if it is assumed that a normalretrieval is possible), gripping units 22′ of the gripping device 22 arepushed into the shelf compartment toward the shelf rear wall 16 and themedication package 30 is gripped (FIG. 1b ).

In the embodiment shown, a clamping gripper is used, so that themedication package 30 is clamped using the gripping units 22′ andsubsequently moved on the shelf base 11 toward the support 21 of theoperating device. As a result of the sagging of the shelf base 11, theend side or end face of the support 21 forms a stop for the medicationpackage 30, as can be seen in FIG. 1c . The stop formed by the end sideor end face of the support 21 prevents the medication package 30 frombeing able to be moved using the gripping device onto the support 21.This is checked using a sensor 24, 25. The sensor 24 is an opticalsensor which checks whether the medication package 30 has been movedcompletely past it. This may be ascertained, for example, on the basisof the (known) size of the medication package 30 and the known movementvelocity (under normal conditions). Also, a contact sensor 25 canascertain whether the medication package was moved completely over it;if this is the case, the sensor is contact-free again after themedication package 30 is moved past completely.

As a result of the sagging of the shelf base 11, the check has anegative result, however, so that an edge 11″, 11′″ of the shelf base11, on which the medication package 30 is stored, is ascertained usingthe sensor 23.

For this purpose, in the exemplary embodiment shown, firstly themedication package 30 is again pushed using the gripping device 22 farenough into the shelf compartment that the top edge 11″ of the shelfbase is free (and therefore detectable). It is described with referenceto FIGS. 3a-3c how this can be carried out in detail. In anotherembodiment, the pushing back of the medication package 30 can beomitted; since the top edge 11″ is then not detectable as usual, theoperating device 20 may be moved downward until the bottom edge 11′″ ofthe shelf base 11 can be ascertained on the basis of the characteristicsignal.

After the medication package has been pushed into the shelf compartment,the operating device is moved downward (along the Z axis) until thesignal characterizing the top edge 11″ is ascertained (FIG. 1e ), usingwhich the actual value (in relation to the Z axis) of the top edge 11″can be determined.

As soon as the edge 11″, 11′″ is ascertained, the operating device 20 ismoved to a correspondingly corrected shelf position (FIG. 1f ) and themedication package is retrieved (see above). The corrected shelfposition is ascertained on the basis of special structural conditions(for example, shelf base thickness, actual value for the edge,construction of operating device).

If pushing back of the medication package is not to be carried out, anascertainment of the top edge 11″ can be carried out as shown in FIG. 4.The point S shows the point of incidence of the measurement beam of thesensor 23 on the medication package 30 according to the position of themedication package 30 shown in FIG. 1c , i.e., pressing against the endside or end face of the support 21. The operating device 20 is movedhorizontally (X axis or X direction) with the sensor 23, wherein themeasurement beam of the sensor 23 runs along the dotted line over themedication package 30. As soon as the measurement beam is guided overthe edge of the medication package (at X position X₁) by the movement ofthe operating device 20, a greater distance is suddenly ascertained(state change in the case of binary distance measurement), since thesensor, after overshooting the X₁ position, measures the distance to theshelf wall 16 or a medication package 30 behind the medication package,which presses against the end face of the support 21. The sensor 23 hasnow detected a region adjacent to the medication package 30 and theoperating device 20 is then moved downward, wherein the pathway of themeasurement beam of the sensor 23 is again identified with a dottedline. As soon as the measurement point, proceeding from the Z positionZ₁, reaches the Z position Z₂, a sudden change of the measured distanceagain occurs, specifically when the measurement beam is incident on thetop edge 11″ of the shelf base 11. This is ascertained as the signalcharacterizing the top edge 11″ of the shelf base 11. As soon as thecharacterizing signal has been ascertained, the actual position of thetop edge 11″ of the shelf base 11 is known and, based on this actualposition, the operating device 20 is moved to a shelf position at whichthe medication package can be retrieved, wherein the “return” in thehorizontal direction is dependent on how far the operating device may bemoved to detect the region adjacent to the medication package.

As soon as the operating device is moved into the corresponding shelfposition, as shown in FIG. 1d , the medication package 30 is moved bythe gripping units 22′ of the gripping device 22 onto the support 21 ofthe operating device 20, wherein this movement of the medication package30 can also be monitored using the sensor. As soon as the medicationpackage has been moved onto the support 21, it is moved using theoperating device 20 to a delivery location in the pharmacy order-pickingdevice.

Still a further embodiment is indicated in FIG. 4, in which theoperating device is moved further downward after the ascertainment ofthe top edge 11″ at the Z₂ position, to ascertain the bottom edge 11′″of the shelf base 11 at the Z₃ position. The thickness of the shelf basecan be ascertained from the ascertained values for the Z₂ and the Z₃positions, and this value can be used for a plausibility check (themedication package is only retrieved if the value for the thickness ofthe shelf base corresponds to a target value).

As can be inferred from FIG. 1c , inter alia, the medication package 30presses against the end side or end face of the support 21 during amethod step. In the above-described embodiment of the method, theoperating device is firstly moved horizontally and then verticallyproceeding from this method step. As a result of the contact of themedication package 30 on the end side of the support 21, the horizontalmovement of the operating device can be disturbed, or the horizontalmovement can push the medication package on the shelf base, which makesa later retrieval more difficult or impossible.

To avoid this, in one embodiment of the method, the medication package30, after it has been established that the medication package 30 has notbeen moved completely onto the support 21, can be pushed back into theshelf compartment using the gripping device 22. This is shown in FIGS.3a-3c , wherein the starting situation shown in FIG. 3a approximatelycorresponds to FIG. 1c , i.e., the medication package 30 presses againstthe end side of the support 21 (reference signs were left out in FIGS.3b and 3c for the sake of clarity).

In the exemplary embodiment shown in FIGS. 3a-3c , three medicationpackages are to be retrieved. The movement back of the medicationpackages 30 can be carried out using the gripping units 22′ (clampingjaws) or the gripping unit 22″ (suction gripper or pusher). In thefirst-mentioned case, the medication package, which presses against theend face of the support 21, may be gripped using the gripping units 22′.All medication packages are then pushed back into the row of shelves viathese gripping units. If the gripping unit 22″ (suction gripper) isused, it is unimportant how many medication packages are to be pushedback into the shelf surface.

After the medication packages have been pushed back into the shelfsurface, it is no longer necessary to move the operating device 20horizontally to ascertain the top edge 11″ of the shelf base 11, since adistance jump medication package/top edge of shelf base would now againbe generated. To ascertain the top edge the shelf base, it is sufficientto move the operating device downward until the signal characterizingthe top edge is ascertained, and optionally to adjust the operatingdevice for the retrieval, wherein this subsequent adjustment (as also inall other embodiments) is dependent on the precise structural embodimentof the operating device 20. For example, upon the ascertainment of thesignal characteristic for the top edge, if the surface of the shelf baseis still arranged lower than the support, readjustment may be performed.

FIGS. 2a-2f illustrate a further embodiment of a method, wherein thestructural features of the pharmacy order-picking device are onlyschematically illustrated. The embodiment shown here is suitable foroperating devices in which the sensor 23 is installed below the support21. The embodiment shown differs only slightly from that shown in FIGS.1a-1f , so that a detailed description will be omitted to avoidunnecessary repetitions.

The operating device 20 is firstly moved in a movement setting to apredefined shelf position (FIG. 2a ), in which retrieval is to beperformed. For the retrieval, the medication package 30 is moved usingthe gripping device 22 on the shelf base 11 toward the support 21 of theoperating device (FIG. 2b ). It is then checked whether the medicationpackage 30 was moved onto the support (for details, see description ofFIGS. 1a-1f ) and if this is not the case, the medication package 30 ispushed back using the gripping device 22 into the shelf compartment(FIG. 2d ), to thus prevent the medication package from being pushedduring a following movement of the operating device upward. Withactivated sensor 23 (measurement beam is illustrated as a dotted line),the operating device is then moved “upward” (in relation to the Z axis),until a signal characterizing the bottom edge 11′″ (for greater detail,see above) is ascertained using the sensor 23 (FIG. 2e ). As soon as thesignal is ascertained, the operating device is moved downward by aspecific value into a correspondingly corrected shelf position (FIG. 2f), wherein the value is dependent on the structural details of theoperating device 20 and the thickness of the shelf base.

FIGS. 5a and 5b show an embodiment of an alternative method forretrieving medication packages from a pharmacy order-picking device. Thepharmacy order-picking device includes a row of shelves having in eachcase a plurality of shelf bases 11 extending in a horizontal directionand a plurality of shelf walls extending in a vertical direction,wherein the shelf bases and the shelf walls form a plurality of shelfcompartments. An operating device 20 which is movable horizontally andvertically is arranged in front of the row of shelves, said operatingdevice comprising a gripping device 22, a sensor 23, and a support 21having a support surface 21′, wherein the sensor 23 is arranged belowthe support 21.

The operating device 20 is firstly moved in a movement setting to apredefined shelf position, at which the at least one medication packageis to be retrieved. Before, in contrast to some methods, the medicationpackage is retrieved, the distance A_(I) between the sensor 23 and thebottom side 13 of the shelf base 11 is ascertained in any case using thesensor 23 (the measurement beam is again shown as a dotted line). The“distance” between the sensor and the bottom side 13 of the shelf baseis in relation to the point of incidence of the measurement beam on thebottom side 13 of the shelf base, which changes in relation to the shelfbase upon displacement of the operating device (and therefore of thesensor). In FIGS. 5a and 5b , this is illustrated with distances d_(I)and d_(D) projected on the X axis, wherein these values do not reproducethe actual distance.

The distance A_(I) is compared to a target value for the distancebetween the sensor 23 and the bottom side 13 of the shelf base 11. Itcan be determined on the basis of the deviation from the target value towhat extent the horizontal alignment between the shelf base and thesupport surface 21′ is disturbed. If a deviation which exceeds alimiting value is not established, the medication package 30 can beretrieved using the gripping device 22 (FIG. 5a ).

However, if a deviation is established, which possibly will prevent aretrieval as a result of the sagging of the shelf base (FIG. 5b ), theoperating device 20 is moved downward by a corresponding amount to acorrected shelf position and the at least one medication package 30 ismoved on the shelf base 11 in the direction of support 21 using thegripping device 22.

1. A method for retrieving packages from a pharmacy order-picking device, the method comprising: providing a pharmacy order-picking device comprising: a shelf comprising a shelf base extending in a horizontal direction and a shelf wall extending in a vertical direction; and an operating device movable horizontally and vertically in front of the shelf, wherein the operating device comprises: a gripping device; a sensor; and a support having a support surface; moving the operating device to a predefined shelf position; moving at least one package on the shelf base associated with the shelf position in a direction of the support using the gripping device; determining whether the at least one package has been stopped by the support; determining, when the at least one package has been stopped, an edge of the shelf base associated with the shelf position; and moving the operating device to a corrected shelf position based on the determined edge.
 2. The method of claim 1, wherein the edge of the shelf base comprises a top edge of the shelf base, and wherein moving the operating device to a corrected shelf position comprises: moving the operating device horizontally until the sensor detects a region adjacent to the at least one package to be retrieved; moving the operating device vertically until a signal characterizing the top edge of the shelf base is ascertained using the sensor; and moving the operating device to the corrected shelf position.
 3. The method of claim 1, wherein the edge of the shelf base comprises a bottom edge of the shelf base and wherein moving the operating device to the corrected shelf position comprises: vertically moving the operating device until a signal characterizing the bottom edge of the shelf base is ascertained using the sensor; and moving the operating device to the corrected shelf position.
 4. The method of claim 1, wherein determining the edge of the shelf base comprises: ascertaining, using the sensor, an actual value of the edge of the shelf base; comparing the actual value to a target value to determine an ascertained deviation, and wherein moving the operating device to a corrected shelf position comprises vertically moving the operating device by a value corresponding to the ascertained deviation.
 5. The method of claim 1, wherein moving the operating device to a corrected shelf position comprises moving the operating device such that the support surface is horizontally aligned with or lower than, within a threshold, a shelf base surface of the shelf base.
 6. The method of claim 1, wherein determining whether the at least one package has been stopped by the support comprises ascertaining a length of the at least one package moved onto the support using a second sensor and comparing it to a target value, wherein a deviation from a target value indicates that the at least one package was stopped by the support.
 7. The method of claim 6, wherein ascertaining the length of the at least one package is based on a known movement velocity of the gripping device.
 8. The method of claim 1, wherein determining whether the at least one package was stopped by the support comprises checking, using a second sensor, whether the at least one package was guided beyond the second sensor.
 9. The method of claim 8, wherein the second sensor is located on the support surface and is in contact with the at least one package when the at least one package is above it, and wherein checking whether the at least one package was guided beyond the second sensor comprises determining whether the second sensor is not in contact with the at least one package after having been in contact with the at least one package.
 10. The method of claim 2, further comprising: responsive to ascertaining the signal characterizing the top edge of the shelf base, moving the operating device further downward; ascertaining a signal characterizing the bottom edge; determining a plausibility check based on the ascertained signals; and moving the operating device to a shelf position corresponding to the top edge of the shelf base when the plausibility check is positive.
 11. The method of claim 1, further comprising: moving the at least one package away from the support using the gripping device such that the at least one package has no contact with an end face of the support, in response to determining that the at least one package has been stopped by the support.
 12. The method of claim 11, further comprising: moving the operating device downward until a signal characterizing a top edge of the shelf base is ascertained using the sensor; and retrieving the at least one package after moving the operating device to the corrected shelf position.
 13. A method for retrieving medication packages, the method comprising: moving an operating device to a predefined shelf position, the operating device comprising a support, a gripping device, and a sensor; moving at least one medication package on a shelf base associated with the shelf position in a direction of the support using the gripping device; determining, with the sensor, an edge of the shelf base if the at least one medication package has not been moved completely onto the support; and moving the operating device to a corrected shelf position based on the determined edge.
 14. The method of claim 13, wherein the edge of the shelf base is a top edge of the shelf base and wherein moving the operating device to a corrected shelf position comprises: moving the operating device horizontally by a distance in a first direction until the sensor detects a region adjacent to the at least one medication package; moving the operating device downward until the top edge of the shelf base is ascertained using the sensor; moving the operating device horizontally by the distance in a second direction, opposite the first direction; and retrieving the at least one medication package.
 15. The method of claim 14, wherein ascertaining the edge of the shelf base comprises detecting a state change in a binary distance measurement.
 16. The method of claim 13, wherein determining the edge of the shelf base comprises: determining, using the sensor, an actual value of the edge of the shelf base; determining a deviation between the actual value and a target value, wherein moving the operating device to a corrected shelf position comprises vertically moving the operating device based on the deviation.
 17. The method of claim 13, further comprising: moving the at least one medication package away from the support using the gripping device such that the at least one medication package has no contact with an end face of the support, in response to determining that the at least one package has not been moved completely onto the support.
 18. The method of claim 13, wherein the corrected shelf position is based on one or more of a shelf base thickness, an actual value of the edge of the shelf base, or construction of the operating device.
 19. A method for retrieving packages from a pharmacy order-picking device, the method comprising: providing a pharmacy order-picking device comprising: a shelf comprising a shelf base extending in a horizontal direction and a shelf wall extending in a vertical direction; an operating device movable horizontally and vertically in front of the shelf, wherein the operating device comprises: a gripping device; a support having a support surface; and a sensor arranged under the support; moving the operating device to a predefined shelf position corresponding to the shelf, the shelf holding a package to be retrieved, the shelf base having a bottom side; determining a distance from the sensor to the bottom side of the shelf base; determining a deviation between the determined distance to a target value for an expected distance between the sensor and the bottom side of the shelf base; moving the operating device vertically to a corrected shelf position based on the deviation when the deviation exceeds a limiting value; and moving the package in a direction of the support using the gripping device.
 20. The method of claim 19, wherein the corrected shelf position is further based on a shelf base thickness and structural details of the operating device. 